ES2640055T3 - Safety provision of an elevator - Google Patents

Abstract

A safety arrangement of an elevator, whose elevator comprises an elevator control system (2), an elevator motor (25), an elevator power supply circuit (1) as well as at least one apparatus (26, 48) mechanical stop to prevent movement of the elevator car (28), and whose safety arrangement comprises: - a measurement arrangement for monitoring the elevator safety spaces - a control unit (3) - a first channel (19 ) data transfer between said measurement arrangement and the control unit (3) - a second data transfer channel (6) between the elevator control system and the control unit (3) and whose measurement arrangement for monitoring the safety spaces of the elevator comprises: - normal operating limit switches (12, 14) at the top and bottom of the elevator shaft to adjust the final limits of movement of the elevator car in ac normal operation, and where the measurement arrangement for monitoring the safety spaces of the elevator comprises: - switches (13, 15) of service space limit at the top and bottom of the elevator shaft to adjust the spaces of service in the elevator shaft, whose service space limit switches are located farther from the ends of the elevator shaft than the normal operating limit switches (12, 14), and whose measurement arrangement for monitoring spaces The safety of the elevator is characterized by: - sensors (7, 7 ', 8) that measure the position of the access door (20) of the elevator, being switches that are connected in series with each other, whose contact is opened when the access door opens, and - the data transfer channel (19) between the control unit (3) and the switches (7, 7 ', 8) comprises a resistor (33, 34, 35) set in the I circulated to series in parallel with the above-mentioned switch, where the resistance (35) set in parallel with the switch (7 ') of the lower floor access door differs in its resistance value from the resistors set in parallel with all other switches (7, 7 ', 8) in order to identify the position of the lowest floor access door.

Description

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DESCRIPTION

Safety provision of an elevator Field of the invention

The present invention relates to a safety arrangement of an elevator as defined in the preamble of claim 1.

Prior art

When modern building elevators are modernized, problems are often encountered because safety standards have changed over the years and free heights and clearance at the bottom in the elevator shaft above and below the Cabin in the elevator shaft are not large enough to meet the requirements of modern safety standards. Expanding the gap up or down is in most cases impossible in terms of construction engineering or at least so expensive and difficult that it is not viable.

A goal in new buildings is to save space in the elevator shaft. This is done by dimensioning the free heights and the free spaces at the bottom in the elevator shaft so that they are as small as possible. In this case there is no longer adequate security space for the protection of personnel above and below the elevator car for a technician working in the elevator shaft or on the roof of the elevator car.

The performance of maintenance work in the elevator shaft has become more general due in particular to the so-called elevators without machine room, because in these elevators the lifting machine and often also the control of the lifting machine are arranged in the elevator shaft and not in the machine room as is conventional.

Often a rotating damper located on the bottom of the shaft is used as a safety device in the service spaces of an elevator shaft. The maintenance technician rotates said shock absorber that can rotate to the operating position before working in the elevator shaft. The rotatable damper may be located below the elevator car above the lower part of the elevator shaft, in which case it limits the movement of the elevator car in the lower space of the elevator, or it may be located under the counterweight, in which case it limits the movement of the counterweight in the lower space of the shaft and simultaneously limits the movement of the elevator car in the upper space of the shaft. When the necessary safety clearance of the upper space of the elevator shaft is dimensioned, it should be noted that in this case when the counterweight collides with the damper at the lower end of the shaft, the elevator car still moves upward at the end upper hole due to its kinetic energy. The length of the movement depends on the maximum possible speed that the elevator car can have in the collision with the counterweight. The safety clearance must therefore be sized to correspond with the maximum possible speed at the time of a collision. In addition, when determining the safety clearance in both the upper and lower spaces of the elevator shaft, the volumetric compression of the shock absorber caused by the collision must be taken into account.

The prior art level is presented in WO 97/2339. This publication describes an apparatus so that it is arranged for the lower safety space of an elevator, in which a support column is arranged in the travel path of the cabin sling, which is turned to the operating state with an actuating element. , which is supported on the floor of the hole and on the support column. The necessary switches, which indicate the position of the support column, are arranged in connection with the support column.

Publication JP03018575 presents a switch installed in connection with a mechanical safety device, the position of whose switch changes at the same time that the mechanical safety device is turned to the operational state. Drive with the elevator motor is only allowed when the switching of the mechanical safety device to the operating state can be read from the change in the state of the switch.

Publication EP1159218B presents a safety device of an elevator, in which an electrical safety device (a safety controller) reads the information of the sensors connected to the elevator system and when it detects that the safety of the elevator system is in danger sends a control signal to the elevator motor controller, to the elevator brake and also to the elevator system control.

Publication EP 1110900 B1 presents a safety arrangement of an elevator, in which the safety switches are provided in connection with the elevator access doors, whose switches are opened when the access door opens over the elevator shaft. The arrangement comprises a safety device, which is activated automatically when the maintenance technician opens the elevator shaft door for maintenance work. The activation occurs in such a way that a safety switch provided in connection with the door lock of the opening is opened when the technician opens the door of the opening with a key. The safety provision also includes temporary limit switches during maintenance, which the control system of the

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elevator reads and on the basis of which monitors the movement of the elevator car in the elevator shaft.

Publication US 2005/0098390 A1 presents a safety arrangement of an elevator, comprising a certain type of control unit, sensors that measure the position of the elevator access doors, a sensor that measures the position of the door of the elevator. elevator car, limit limit sensors in connection with both ends of the elevator shaft, and also a data transfer channel between the door sensors and the control unit.

Publication US 2006/0157305 A1 presents a safety arrangement of an elevator, comprising sensors in connection with the access doors of the elevator to detect the position of the access doors, a sensor in connection with the door of the elevator car , limit limit sensors in connection with both ends of the elevator shaft, a sensor in connection with the damper, a control unit, which reads the information from the sensors, and also a data transfer channel between the sensors and the control unit

JP 2006-199404 describes a safety device for an elevator that prevents a cabin provided with a folding safety grill on an upper part from interfering with the uppermost part of the hollow or with the lower part of the hollow. When a maintenance mode is activated by a switch on the cabin, the maintenance operation is only possible, however, when a folding detector detects an erect state of a security fence where interference from the security fence and the part Higher hole is prevented. The cabin is raised / lowered between an action point of a maintenance operation upper limit switch to secure the work space on the upper part of the cabin and an action point of a lower operating limit switch of usual operation to prevent cabin interference.

US 6,193,019 B1 shows the equipment of a security chain for access doors with different resistances to easily recognize the specific door in which its locking mechanism has malfunctioned.

Also in accordance with US 6,173,814 B1 it has been known to install an electronic security system that has a central controller to monitor a variety of door sensors, contacts and switches on an electronic security bus.

At least, document US 6.223861 B1 shows a safety circuit of an elevator, which monitors the condition of the doors of the shaft and the door of the elevator, where the opening of a door of the shaft is not accompanied by the opening of the cabin door to be an indication of access to the hole. In this case then the elevator system is operated in a low speed inspection mode. In addition, inspection speed limit switches have been installed near the top and bottom of the shaft positioned so that if they are operated while the elevator is traveling at inspection speed, the cabin will stop in one position. which leaves a person ample space from the top of the hole or the floor of the pit.

Purpose of the invention

The purpose of the invention is to present a security arrangement for establishing the safety spaces of an elevator in the elevator shaft. A purpose of the invention is to describe a security arrangement that is centrally monitored with an electric control unit, which is simpler than the prior art and more diversified in its operating methods than the prior art.

Characteristic features of the invention

The safety arrangement of an elevator according to the invention is characterized by what has been described in the characterization part of claim 1. Other features of the invention are characterized by what has been described in the other claims. Some embodiments of the invention are also discussed in the descriptive section of the present application.

The present invention relates to a security arrangement of an elevator.

In a safety arrangement of an elevator according to the invention, the elevator comprises an elevator control system, an elevator motor, an electric power circuit of the elevator motor as well as at least one mechanical stopping apparatus to prevent movement from the elevator car. The security arrangement according to the invention further includes:

- a measurement arrangement to monitor the safety spaces of the elevator

- a control unit

- a first data transfer channel between the measurement arrangement to monitor the spaces of

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elevator and control unit safety

- a second data transfer channel between the elevator control system and the control unit

The measurement arrangement for monitoring the safety spaces of the elevator according to the invention comprises limit switches of normal operation in the upper part and in the lower part of the elevator shaft to establish the final limits of movement of the elevator car in normal drive

The measuring arrangement for monitoring the safety spaces of the elevator in accordance with the invention comprises service space limit switches at the top and bottom of the elevator shaft to establish the service spaces in the elevator shaft, whose service space limit switches are located farther from the ends of the elevator shaft than the normal operating limit switches.

An elevator control system generally refers to a control arrangement that is needed to drive the elevator from floor to floor according to elevator calls. Thus, this elevator control system comprises at least the regulation of the call processing of the car, the traffic processing of the elevator and the movement of the elevator car. The power circuit of the elevator motor refers to a circuit with which the power needed to move the car is supplied to the motor of the elevator car. This type of circuit can be, for example, the main current circuit of a frequency converter.

The elevator motor can be a rotating motor or a linear motor. The engine can be arranged in the elevator shaft or in a machine room. The mechanical stopping apparatus may be a device that may be connected in a manner that brakes a mobile part of the elevator machine or, for example, a device that may be connected to the crane lane of the elevator car in a manner Stop the elevator car.

The measurement arrangement for monitoring the safety spaces of the elevator refers to measurements located at different points that are important from the security point of view for the elevator system, by means of which the state of the safety spaces of the elevator Elevators, such as the safety spaces in the elevator shaft, are monitored and defined. For example, the position of the access doors of the elevator shaft is measured with the safety switches of the access doors and with the electronic reading of the switches.

The control unit reads information from the measurement arrangement to monitor the safety spaces of the elevator and on the basis of the measurements makes inferences about the safety spaces. The control unit can for example read the position information of the doors of the elevator shaft and, if there is one, of the elevator car and deduces on the basis of the position information if an elevator installer has moved inside the elevator. elevator shaft In this case the control unit can switch to the person mode in the elevator shaft and limit the appropriate safety spaces in the elevator shaft for the work of the elevator installer. When it detects that safety is in danger, the control unit can control one or more mechanical stop devices.

The control unit can be implemented, for example, with a microcontroller, with a programmable logic circuit, with programmable logic or with relays. The control unit may also comprise at least two microcontrollers, or some other independent logic control, that operate independently of one another and additionally communicate with each other through a separate communication channel and thus monitor the operation of both in order to improve the security of the control unit.

A first data transfer channel refers to a channel between the control unit and the measurement arrangement to monitor the safety spaces of the elevator. The measurement arrangement for monitoring the safety spaces of the elevator comprises sensors, and electronic can be installed to read the measurement signals of the sensors in connection with the sensors. A transmitter and / or a receiver, which are connected to the first data transfer channel to send sensor information to the control unit, can be additionally installed in connection with the sensors. A transmitter and / or a receiver can also be provided in connection with the control unit, through which a read request is sent to the measurement device to read the sensor information and through which the sensor information that arrives from the measurement provision is lefda.

A second data transfer channel is provided between the elevator control system and the control unit. The control unit is intended to send at least information about its mode of operation to the elevator control system through the second data transfer channel. If, for example, the control unit has changed to the service drive mode, you can send information about this to the elevator control system, in which case the elevator control system limits movement to an area allowed in the recess of the elevator, and does not attempt to operate the elevator car towards the reserved area as the technician's safety space. In order to limit the movement of the elevator car in the elevator shaft, the elevator control system needs some information about the position of the elevator car in the elevator shaft. This information can, for example, come from an encoder provided in connection with the lifting machine or the elevator car or from the position sensors of the elevator car, such as from the limit switches of the elevator shaft. If, on the other hand, the control unit has changed to the operating mode prevented, in addition to preventing the movement of the elevator car by controlling a device

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Stop mechanic, also send information about the drive mode prevented to the elevator control system through the second data transfer channel. In this case, the elevator control system does not attempt in vain to start the elevator.

In a safety arrangement of an elevator according to the invention the control unit comprises:

- a control of the mechanical stopping apparatus, and

- means for disconnecting the power supply circuit of the elevator motor

and the measurement arrangement for monitoring the safety spaces of the elevator according to the invention comprises:

- sensors that measure the position of the elevator access door

The control of the mechanical stopping apparatus may comprise, for example, a controllable switch in the power supply circuit of the machinery brake, and the control unit may contain an output for the control signal of the controllable switch. The control unit can, by controlling the switch, open the power supply circuit of the machinery brake and thus prevent the opening of the machinery brake. The mechanical stopping apparatus can also be, for example, a rail brake that stops the elevator car from the rail. The control of the mechanical stopping device may in this case comprise the power supply of the crane control of the rail brake. The control unit can also be provided to prevent the supply of energy to the crane rail brake control, in which case the cabin brake does not open and the elevator car is not able to move.

The mechanical stopping device can also be for example a cradle brake connected to the rails of the elevator car. The control of the cradle brake can be produced in accordance with the prior art through the mechanical over-speed regulator cable. A solenoid can also be in connection with the pulley of the mechanical over-speed regulator cable, which can be controlled closed against the pulley of the cable in order to block it. The control unit may in this case comprise the solenoid control. The control unit can activate the operation of the cradle brake, that is to say, grab the crane rail, stopping the pulley of the over-speed regulator cable with the solenoid control in the middle of an elevator path, in which case starts up the grna rail grip.

The measurement arrangement for monitoring the safety spaces of the elevator according to the invention comprises a sensor that measures the position of the elevator car door in connection with the elevator car door operator.

A measuring arrangement for monitoring the safety spaces of the elevator according to the invention comprises service drive sensors at the top and bottom of the elevator shaft to establish the final limits of movement of the elevator car in operation. of service, whose service drive sensors are located farther from the ends of the elevator shaft than the service space limit switches.

In a safety arrangement according to the invention the control unit comprises operating modes, at least one normal drive mode, a person mode in the elevator shaft, a permitted service drive mode, and a drive mode. prevented. The control unit is set to recover from other operating modes back to normal drive mode under the control of a manually operated return device.

In a security arrangement elevator according to the invention the control unit is provided to monitor the movement state of the elevator car. After the elevator car has reached the service space limit switch at the bottom of the elevator shaft from above, the control unit is intended to allow the elevator car to move only upwards. After the elevator car has reached the service space limit switch at the top of the elevator shaft from below, the control unit is adjusted to allow movement of the elevator car only downwards. After the elevator car has reached the service space limit switch, the control unit stops the elevator car by controlling, for example, the rail brake. After this the control unit can send information about this to the elevator control system. The elevator control system can send the type of drive request to the control unit from which the drive address is evident, and if this corresponds to the allowed drive address of the service space limit switch, the unit Control allows travel and opens the rail brake. On the other hand, the control unit can also measure the direction of movement of the elevator car, and then the opening of the brake of the control unit can on the basis of the measurement deduce if the elevator car is leaving the limit switch of service space in the permitted drive address. If the direction of movement of the elevator car is deducted from that allowed, the control unit immediately stops the elevator car by controlling the brake.

The switches mentioned above in the measurement arrangement for monitoring the safety spaces of an elevator can be for example space safety switches or normal safety switches, whose

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Contacts are duplicated to increase security. For example, the sensors that measure the position of the elevator access door can be safety switches, whose contacts are opened under forced control when the access doors are opened.

In a security arrangement according to the invention, the sensors provided in connection with the elevator access doors are bi-stable switches that open and remain open when the access doors are opened. In addition, means can be arranged in connection with the switches to then close the switches.

The service drive sensors are limit switches located in the service drive limit in the elevator shaft, or for example magnetic switches. In this case, a magnet may be arranged at the service drive limit in the elevator shaft, and on the elevator car there may be a magnetic switch, which reacts to the magnetic field of the magnet provided in the service drive limit and by by means of which it is thus possible to detect the arrival of the elevator car in the service drive line. The service drive limit refers to the first limit point, which is located farther from the end of the elevator shaft than the service space limit switch and by means of which it is detected that the elevator car is approaching the switch of service space limit. The control of the elevator car stop apparatus may be arranged in such a way that when the elevator car reaches the service drive sensor the machinery brake is controlled to stop the elevator car. However, if the elevator car continues its journey to the service space limit switch, the stopping device that holds the crane rail of the elevator car is also controlled, and thus an attempt is made to ensure the car stop. elevator.

In a safety arrangement according to the invention after the elevator car has reached the service drive sensor, the control unit stops the elevator car by controlling the machinery brake. After this the control unit allows the elevator control system to start another new route. If during the new route the elevator car continues its journey towards the end of the elevator shaft reaching the service space limit switch, the control unit controls the stopping device that holds the crane lane of the elevator car and switches to the disabled drive mode, in which case a new ride with the elevator is no longer allowed before the disabled drive mode is canceled using the manually operated return device.

A safety arrangement according to the invention comprises both a machine brake and a cabin brake to prevent movement of the elevator car in the elevator shaft. A control unit according to the invention comprises a control of both the machine brake and the cabin brake.

A measuring arrangement for monitoring the safety spaces of the elevator according to the invention comprises at least one sensor that measures the status of the service drive switch in connection with the service drive unit of the elevator. The service drive switch may be a manually operated switch, which is located in the elevator shaft, for example in the roof of the elevator car. When a maintenance technician moves in this case on the roof of the elevator car, the service drive switch is turned to the position that allows the service drive. The control unit reads the status of the service drive switch and allows the service drive within a restricted area in the elevator shaft.

According to the invention the sensors that measure the position of the elevator access door are switches that are connected in series with each other, whose contact is opened when the access door is opened.

According to the invention, the data transfer channel between the control unit and the series circuit of the switches comprises a resistance provided in the series circuit in parallel with each switch mentioned above.

In accordance with the invention, the resistance provided in parallel with the lower floor access door switch differs in its resistance value from the resistors set in parallel with all other switches in order to identify the position of the door of access of the lowest floor. In this case, a limit value for the current can be set, on the basis of which it is possible to detect the opening of the lowest floor switch. It is possible to deduce on this basis that the maintenance technician has moved to the bottom of the elevator shaft, in which case safety spaces can be established at the lower end of the elevator shaft. Similarly, when the opening of a switch of an access door of a different floor of the lower floor is detected, it can be deduced that the maintenance technician has moved on the roof of the elevator car and in this case the Safety spaces can be established at the upper end of the elevator shaft.

In a security arrangement according to the invention the aforementioned resistance is preferably an encapsulated film resistor. The structure of the resistance of the film is such that the resistance element is well protected for example against dirt. In this case a resistance malfunction such that the resistance element suffers a short circuit is very unlikely.

A control unit according to the invention comprises means for measuring the total resistance of the series circuit.

A measurement arrangement for monitoring the safety spaces of the elevator according to the invention comprises a position sensor that measures the position of the elevator car in the elevator shaft. The position sensor can be, for example, an impulse encoder provided in connection with the lifting machine or with the elevator car, from where the position is determined by integrating the impulses. The position information can also be read 5 in another way, for example by means of transceiver pairs that process an acoustic or electromagnetic signal provided on the elevator car and at the ends of the elevator shaft. An acceleration sensor can also be arranged on the elevator car, and the position information can be determined by first integrating the speed and then the position information from the acceleration signal. The control unit can read the measured position information and if necessary compare it with some other measurement of position information. By comparing the measurements the control unit can also ensure that the measurements are correct.

A measurement arrangement for monitoring the safety spaces of the elevator according to the invention comprises means provided on the elevator car to measure a change in the speed of the elevator car. In one embodiment of the invention the movement of the maintenance technician on the roof of the elevator car is evaluated based on the acceleration data of the elevator car. In other words, in this case the premise

is that the movement of the maintenance technician on the roof of the elevator car causes vibration, which can be measured.

In a security arrangement according to the invention, the first data transfer channel comprises a first and a second data channel, and both the control unit and the measurement arrangement for monitoring the 20 safety spaces of the elevator are provided for communicate redundantly to the first and second channels of

data, in which case the same data is sent to both data channels in duplicate and independently between sf.

The invention for establishing the safety spaces of an elevator works when:

- the information is read with the control unit from the sensors that measure the position of the door

25 elevator access

- the information is possibly read from the sensors that measure the position of the elevator car door

- if on the basis of the measurements it is detected that an access door opens on the elevator shaft,

- the control unit is changed to the person mode in the elevator shaft and

30 - the elevator drive is avoided by controlling at least one mechanical stopping device

- information about the person mode in the elevator shaft is sent with the control unit to the elevator control system

In addition, after the control unit has changed to the person mode in the elevator shaft:

- the service drive switch sensor is read with the control unit and if it has been detected that

35 the service drive switch has changed to the service drive mode

- the control unit is changed to the permitted service drive mode and

- The status of the service drive limit switches is read with the control unit

- if a service space limit switch is detected as being open, the control unit switches to the operating mode prevented

40 When the access doors open over the elevator shaft, the elevator car is not located in the location of the access door, in which case the movement of a person inside the shaft is possible. In the method it is possible to read information at least about how many access doors or cabin doors are open from the sensors that measure the position of the elevator access door as well as from the sensors that measure the position of the elevator car door. If more open access doors are detected than the open doors 45 of the elevator car, it can be deduced in this case that the maintenance technician has moved inside the gap and in this case the control unit can be changed to the so-called mode of person in the elevator shaft. The maintenance technician can move inside the elevator shaft for example by opening the access door lock with a key equipped for the purpose.

In the person mode in the elevator shaft, the elevator drive is prevented. The control unit 50 ultimately handles this by controlling the mechanical stopping apparatus that prevents movement of the elevator car. When the maintenance technician turns the service drive switch located in the recess of the

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elevator, for example on the roof of the elevator car, to the service drive position, the control unit reads the change of state of the switch and allows the service drive. In this case the control unit also limits the movement of the elevator car in service drive to the allowed area defined with the service space switches. In practice this occurs in such a way that when the elevator car reaches the service space limit switch the switch opens, the control unit reads the switch opening and prevents movement of the elevator car by controlling at least a mechanical stop device.

The control unit can also monitor the movement of the elevator car in service operation in a direction-dependent manner, such that when the elevator car reaches the service space limit switch located at the lower end of the gap of the elevator from above, the control unit prevents movement of the elevator car down, but allows movement upwards. Similarly when the elevator car reaches the service space limit switch located at the upper end of the elevator car in the direction from below, the control unit prevents movement of the elevator car upwards, but allows the movement down. It is also possible that only the service space limit switch located at the upper end or at the lower end of the recess is activated depending on whether the maintenance technician has moved to the bottom of the elevator shaft or on the roof of the the elevator car

A manually operated switch to cancel the person mode in the elevator shaft can also be connected to the control unit.

The control unit can also be provided to switch to the person mode in the elevator shaft always after that in combination with a power outage if also the reserve drive, such as an accumulator, has ceased to supply operating electricity. at the disposal of security. In this case the operation with the elevator is not possible before the maintenance technician visits the place to cancel the person mode in the elevator shaft. This prevents a dangerous situation, which could arise when a person moves into the elevator shaft after the loss of electricity from the security provision.

In addition, after the control unit has switched to the prevented drive mode:

- the movement of the elevator car in the elevator shaft is prevented by controlling the cabin brake with the control unit and

- the operation of the elevator is prevented by controlling the power supply circuit of the open elevator motor with the control unit

In this context, the cabin brake refers to any brake apparatus that is the one that can be mechanically connected to the crane rail of the elevator car, such as a rail brake or cradle brake.

In addition, the switches that determine the position of the access door are arranged in series in a series circuit and the resistors that are equally large are provided in parallel with the switches. In the above mentioned method:

- The voltage is supplied with the control unit to the series circuit through the series resistor connected to the voltage output of the control unit

- The current flowing in the series circuit is measured

- The measured current is compared with at least predefined limit values of current R1, R2, ..., Rn, whose limit values are selected based on the number of switches that are open

- If the current is greater than the predefined limit value R1, it follows that all switches of the access doors set to the series circuit are closed

- If the measured current is within the range R2, ..., Rn of the predefined limit value of the current, the number of the switches that are open is deducted in such a way that the lower limit value Rn corresponds to the largest number of switches that are open and when the value of the current increases the number of switches that are open decreases

When all circuit breakers in the series circuit are closed, only the series resistor connected to the voltage output of the control unit limits the current flowing in the circuit. If one of the switches is opened, the current begins to move through the resistance provided in parallel with the switch, in which case the resistance also begins to limit the current. The current decreases when the number of open switches increases, in which case by means of a measurement of the series circuit current the number of switches that are open can be detected.

In carrying out the invention a separate series resistor is not necessarily needed at the voltage output of the electrical safety device. In this case the voltage output current is limited with some other method,

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for example by means of an active current limitation circuit formed by means of transistors.

In the method, the resistance provided in parallel with the access door switch of the lowest floor differs in its resistance value from the resistors provided in parallel with all other switches in order to identify the position of the access door from the lowest floor. In the above mentioned method:

- The voltage is supplied with the control unit to the series circuit through the series resistor connected to the voltage output of the control unit.

- The current flowing in the series circuit is measured

- The measured current is compared with at least the following predefined current values:

to. with the lnriite R1 value, which corresponds to the current value when all the switches are closed

b. with the limit value R2, which corresponds to the current value when the access door switch only on the lowest floor is open

C. with the limit value R3, which corresponds to the value of the current when the switch of an access door of a floor that differs from the lowest floor is open

- if the current measured in the person mode in the elevator shaft corresponds within a predefined tolerance to some limit value specified in at least points a, boc, the positions of the access door switches are deducted as follow:

- if the measured current corresponds to the limit value of point b, it follows that the maintenance technician has moved to the bottom of the gap and the movement of the elevator car down is limited to the end at the limit switch of service space at the bottom of the elevator shaft

- if the measured current corresponds to the limit value of point c, it follows that the maintenance technician has moved to the ceiling of the elevator car and the movement of the elevator car up is limited to the end at the limit switch of service space from the top of the elevator shaft.

In the method:

- The current entering the series circuit is measured

- The current returning from the series circuit is measured

- The current entering the series circuit and the return of the series circuit are compared to each other

- If the values of the incoming current and the return current differ from each other by more than one limit value

predefined, a deduction is made about the malfunction of the series circuit, the operation of the elevator is prevented by controlling at least one mechanical stop device (26) with the control unit (3) and

- A fault notification containing a command to prevent the drive with the control unit (3) is sent to the elevator control system.

By measuring the current entering the series circuit and returning from the series circuit it is possible to deduce the malfunction of the series circuit, for example a ground fault.

Advantages of the invention

The invention achieves at least one of the following advantages:

With the arrangement according to the invention, the person mode in the elevator shaft can be identified more simply than with the prior art by adding only one resistor in parallel with each access door contact.

Since in the security arrangement according to the invention the elevator safety spaces are monitored with a separate control unit, the signals to be monitored can be filtered using a software program in the control unit according to need. . In this case the system is immune to short-term breaks in the contacts of the switches. When the operational disturbances of the elevator system caused by these short-term breaks decrease, the reliability and the utilization rate of the elevator system improve.

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The safety arrangement according to the invention requires a very complex logic of operation so that it is possible to ensure that the system detects all possible failure situations. The logic used must exclude all modes of operation in which the service drive is prohibited and allow those modes of operation in which the service drive is allowed. In addition, the system must be able to deduce the malfunction of the sensors. In the security arrangement according to the invention, the monitoring of the operation is performed centrally in an electrical safety device, which simplifies the implementation in comparison with a solution implemented with different components. At the same time the total amount of components in the system decreases and the reliability of the system improves.

The electrical safety system according to the invention contains separate normal operating limit switches as well as service space limit switches. Since in the security arrangement according to the invention both the choice about when and which limit limit switches are used and the deduction about the mode of operation of the safety arrangement are made centrally with an electrical safety device, it is possible to ensure that the operating mode of the safety arrangement established by the control unit by means of measurements of the safety spaces corresponds to the limb limit sensors used. When the limit limit sensors are read with the control unit it is possible to ensure that the service space limit switches are in use in a situation where the maintenance technician is in the elevator shaft.

By means of the electrical safety device it is also possible to allow the logical reading of the service space limit switches to depend on the direction, in which case the movement of the elevator car away from the service space limit switch is prohibited. Only in one direction and movement away from the service space limit switch is possible to recover from the fault situation. In addition, it is possible for the control unit to use only the service space limit switch at the top or bottom of the elevator shaft, and the normal operating limit switch located closer to the end of the hole The elevator can be used as a second limit switch. In this case the service drive is possible in a larger area of the elevator shaft.

When the switches incorporated in the safety arrangement are read in the manner presented in the invention by measuring the current that travels through the resistors provided in connection with the switches, the state of the switches connected in series can be determined with the unit of control by means of only a current measurement. This simplifies the interface between the control unit and the readable switches. When resistors of encapsulated film are used in parallel with the switches, the malfunction of a resistor due to a short circuit is very unlikely. Since the failure of a breakage resistance is always detectable with the control unit, it is possible by means of the resistors to also measure the safety circuits, such as the series circuit of the switches of an access door. Resistors are also cheap as components to use in measurements. If resistances of different sizes in terms of their magnitude are provided in parallel with the switches of the access door of the lower floor than those in parallel with the switches of the access doors of the other floors, there is a possibility of detecting the opening of the access door in particular of the lowest floor with the current measurement. In this case it can be deduced if the elevator installer has moved to the bottom of the shaft or on the roof of the elevator car.

In the security arrangement according to the invention it is possible to read the sensors centrally. A serial bus can be arranged between them or they can be connected in series. In this case the amount of wiring is reduced.

In the security arrangement according to the invention it is also possible to monitor the operation of the different sensors with the control unit, and any malfunction can be detected. In addition, it is possible to distinguish a fault situation from an individual sensor and it is possible to send information about this directly to the service center, in which case the system diagnostics improve.

When the amount of separate components, such as relays, in the safety provision decreases, the characteristic problems of these components that are caused by wear and that limit the useful life also decrease

Presentation of the drawings

Next, the invention will be described in more detail with reference to the attached drawings, in which

Fig. 1 presents a security provision according to the invention

Fig. 2 presents a top view of an elevator car 28 according to fig. one

Fig. 3 presents a measurement arrangement to monitor the safety spaces of the elevator

Realizations

Fig. 1 presents an elevator, in which the security arrangement according to the invention is applied. Cabin 28

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of the elevator is intended to move in the hollow 27 of the elevator from floor to floor 21, 22. This elevator system according to this invention also contains a counterweight 23, but the elevator system according to the invention can also be without counterweight . The elevator motor 25 is located in the elevator shaft, but it can also be located in a machine room.

In one embodiment of the invention, the limbs of movement of the elevator car in the elevator shaft are established by the limit limit sensors 12, 13, 14, 15, 45, 46. During normal operation, the elevator car travels between the limit limits defined by the limit limit switches 12, 14. After the maintenance technician has moved into the elevator shaft, the control unit 3 first changes to the person mode in the elevator shaft. In this case, the control unit prevents the operation of the elevator by controlling the mechanical device 26, 28. The control unit can also read the position of the service drive switch 5 and when it detects that the position of the switch has changed to the service drive mode, the control unit switches to the allowed service drive mode, in which case the Service drive can be operated with the elevator in the area in the elevator shaft determined by the service space switches 13, 15 and possibly also by the service drive sensors 45, 46. If the service drive sensors 45, 46 are provided in the elevator shaft, the service drive is allowed only in the area between the service drive sensors. When the elevator car for example arrives at the service drive sensor 45 at the bottom of the elevator shaft, the control unit 3 reads the status of the service drive sensor and controls the machinery brake to stop the elevator car . However, if the elevator car continues its movement in progress to the service space limit switch 13, the control unit controls the crane rail brake 48 of the elevator car to stop the elevator car and in this case The control unit also switches to the disabled drive mode. After the control unit has changed to the drive mode prevented the drive is prevented until the prevention mode is canceled by means of the manually operated cancellation apparatus 41. The cancellation apparatus is connected to the first data transfer channel 19, and the control unit reads the status of the cancellation apparatus through the first data transfer channel. If there are no service drive sensors 45, 46 in the elevator shaft, it is possible to operate a service path with the elevator in the area between the service space limit switches 13, 15. In this case, when the elevator car reaches the service space limit switch, the control unit controls the lane brake 48.

The control unit 3 reads the switches 7, 7 ', 8 which measure the position of the access door as well as the switch 29 which measures the position of the elevator car door through the first data transfer channel 19 and deduces on the basis of the position of these change the security arrangement to the person mode in the elevator shaft. In this case, both the normal drive and the elevator service drive are prevented. The control unit 3 also reads the manually operated switch, that is the service drive switch 45, which expresses the status of the elevator service drive unit through the first data transfer channel 19. When the maintenance technician turns the switch to the service drive position, the switch opens. After the service drive switch 5 has changed to the service drive mode the control unit 3 allows the service drive.

In this embodiment of the invention the control unit also reads the normal operating limit switches 12, 14, the service space limit switches 13, 15, and the service drive sensors 45, 46 through the first channel 19 data transfer.

Fig. 2 also presents a second embodiment of the invention, in which the readers 43, 44 of the limb limit sensors are arranged in connection with the elevator car. In this embodiment of the invention ramps are used as limb limit sensors and switches are used, which can be brought into contact with the ramps, such as the readers of the limb limit sensor.

In this embodiment, the elevator shaft contains two different limb limit sensors to establish the limitation limits of the elevator's movement. With normal operation it is possible to drive closer to the limb in accordance with ramps 12, 14. In service mode the limbs of movement limitation are limited with ramps 13, 15. Control unit 3 reads the position of the elevator car in the elevator shaft with switches 43, 44 and stops the elevator when it is operated beyond the ramp by controlling the rail brake 48. The switch opens when it makes contact with the ramp. In this embodiment of the invention the switches are intended to be interspersed with the ramps so that switch 43 reads ramps 12 and 15 and switch 44 reads ramps 13 and 14. This is done by arranging ramps 12 and 15 in the elevator shaft in such a way that they are arranged in the movement path of the switch 43, and the sensors 13 and 14 in such a way that they are in the movement path of the switch 44, when the elevator car moves in the hollow of the elevator.

The control unit 3 prevents both the service drive and the normal drive when it detects that both switches 43 and 44 are open. If only switch 43 is open, the upward service drive is prevented. If, on the other hand, only switch 44 is open, the downward service drive is prevented.

The control unit 3 makes a deduction about the operating mode of the security arrangement of the

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elevator. When it detects an operational deviation based on the information it reads from the sensors, it controls the machine brake 26 and / or the 48 lane brake 48. It also sends an impeded drive command to the elevator control system 2 through the second data transfer channel 6.

When the control unit detects the person mode in the recess, it records information about this in the non-volatile memory of the security device. After this the control unit can return to a mode that allows normal operation only by means of the manually operated return apparatus 41. In the security arrangement according to fig. 1 the manually operated return apparatus is disposed on the lowest floor of the elevator shaft and the control unit reads the status of the return apparatus through the first data transfer channel 19. The manually operated return apparatus 41 can also be arranged directly in connection with the control unit 3 and the control unit 3 can read the status of the return apparatus 42 through its own separate connection channel.

Fig. 3 presents an apparatus according to the invention, with which the operation mode of the switches 7, 7 ', 8 of the safety arrangement can be read. These switches are connected to a series circuit and the resistors 33, 34, 35 are provided in parallel with them. The series circuit is connected to the control unit 3. With the control unit a voltage 30 is supplied to the series circuit through the resistor 32 in series. In addition, the apparatus comprises means 31, 42 for measuring the current that travels in the series circuit.

With the control unit 3 a known voltage 30 is supplied to the series circuit through the resistor 32 in series. When the switches 7, 7 ', 8 are closed, the current that travels in the series circuit is limited only by the resistor 32. In this case the current can be measured with the measuring devices 31, 42 and therefore You can read the status of the series circuit. When one of the switches opens, the path of the current through the switch is disconnected and the current begins to move through the resistance provided in parallel with the switch. For example, when the switch 7 is opened, the current begins to move through resistor 33. Simultaneously, the current that travels in the series circuit decreases because the series connection of resistors 32 and 33 restricts the passage of the stream. If, in addition, switch 8 opens, the current decreases even more because the series connection of resistors 32, 33 and 34 restricts its passage. When measuring the current that is displaced in the series circuit with the measuring devices 31.42, it is possible to detect a change in the current and simultaneously a change in the state of the switches of the series circuit corresponding to the change of current .

When resistances of the same size in terms of their resistance values are in parallel with all switches 7, 7 ', 8, the opening of one or more switches can be detected by means of current measurement. The more switches are open, the lower the current that travels in the series circuit. In this case, however, it is not possible to identify which specific switch is open. On the other hand, if a resistance that differs from the others in its resistance value is selected as the resistance 35 connected in parallel with the switch 7 'of the lowest floor, the state of the switch 7' of the lowest floor can be detected. In this case, when the resistors are selected, the combinations of the different resistors must also be taken into account in such a way that the value of the lowest floor resistance always differs in combinations of a series circuit of two or more different resistors so that the detection of the state of the switch 7 'of the lowest floor is possible.

With the apparatus according to fig. 3 It is also possible to detect the malfunction of the series circuit, for example a ground fault. In this case, the current entering the series circuit from the control unit 3 is measured with the measuring device 31 and the current returning to the control unit 3 from the series circuit is measured with the measuring device 42 . In the case of a ground fault part of the current supplied to the series circuit passes from the series circuit to other structures at the point of the short circuit and only one part returns back to the control unit 3 along the circuit in Serie. The return current is measured with the measuring device 42, and comparing the current left by the series circuit and the current returning to the series circuit a fault situation can be detected.

The invention has also been described with the help of a few examples of its realization. It is obvious to the person skilled in the art that the invention is not limited to the embodiments described above, but that many other applications are possible within the framework of the concept of the invention defined by the claims presented below.

Claims (12)

5 10 fifteen twenty 25 30 35 40 Four. Five 1. A safety arrangement of an elevator, whose elevator comprises an elevator control system (2), an elevator motor (25), an electric power supply circuit (1) of the elevator as well as at least one apparatus (26, 48) stop mechanic to prevent movement of the elevator car (28), and whose safety provision includes: - a measurement arrangement to monitor the safety spaces of the elevator - a control unit (3) - a first data transfer channel (19) between said measurement arrangement and the control unit (3) - a second data transfer channel (6) between the elevator control system and the control unit (3) and whose measurement disposition to monitor the safety spaces of the elevator comprises: - normal operating limit limit switches (12, 14) at the top and bottom of the elevator shaft to adjust the final limits of movement of the elevator car in normal operation, and and where the measurement arrangement to monitor the safety spaces of the elevator comprises: - service space limit switches (13, 15) at the top and bottom of the elevator shaft to adjust the service spaces in the elevator shaft, whose service space limit switches are located farther of the ends of the elevator shaft than the normal operating limit switches (12, 14), and whose measurement provision to monitor the safety spaces of the elevator is characterized by comprising: - sensors (7, 7 ', 8) that measure the position of the elevator access door (20), being switches that are connected in series with each other, whose contact is opened when the access door is opened, and - the data transfer channel (19) between the control unit (3) and the switches (7, 7 ', 8) comprises a resistor (33, 34, 35) set in the series circuit in parallel with the switch mentioned above, where the resistance (35) set in parallel with the switch (7 ') of the lower floor access door differs in its resistance value from the resistors set in parallel with all other switches (7, 7 ', 8) in order to identify the position of the access door of the lowest floor. 2. A safety arrangement of an elevator according to claim 1, characterized in that the control unit (3) comprises: - a control of the mechanical stop device (26, 48), and - means for disconnecting the power supply circuit (1) from the elevator motor 3. The security arrangement according to any one of the preceding claims, characterized in that the measurement arrangement for monitoring the safety spaces of the elevator comprises a sensor (29) that measures the position of the elevator car door in connection with the elevator car door operator. 4. The safety arrangement according to any of the preceding claims, characterized in that the measuring arrangement for monitoring the safety spaces of the elevator comprises service actuation sensors (45, 46) at the top and bottom of the recess of the elevator to adjust the final limits of movement of the elevator car in service drive, whose service drive sensors are located farther from the ends of the elevator shaft than the service space limit switches (13, 15). 5. The safety arrangement according to any of the preceding claims, characterized in that the control unit (3) comprises the operating modes, at least one normal operating mode, a person mode in the elevator shaft, a permitted mode of service drive, and an impeded mode of operation, and by which the control unit is adjusted to recover from other modes of operation to a normal drive mode with the control of a manually operated return apparatus (41). 6. The safety arrangement according to any of the preceding claims, characterized in that the control unit (3) is adjusted to monitor the state of movement of the elevator car and why after the elevator car (28) has Once the service space limit switch (13) of the lower part of the elevator shaft has been reached from above, the control unit is adjusted to allow movement of the elevator car only upwards and because after the elevator car has reached the service space switch (15) of the upper part of the elevator shaft from below, the control unit is adjusted to allow the movement of the car cabin lift only down. 7. The safety arrangement according to any of the preceding claims, characterized in that the safety arrangement comprises both a machine brake (26) and a cabin brake (48) to prevent the movement of the elevator car in the elevator shaft and why the control unit (3) comprises a control of both the machine brake and the cabin brake. 8. The security arrangement according to any of the preceding claims, characterized in that the security arrangement for monitoring the elevator safety spaces comprises a sensor (5) measuring the 10 status of at least one service drive switch in connection with the elevator service drive unit (4). 9. The security arrangement according to claim 1, characterized in that the aforementioned resistance (33, 34, 35) is preferably an encapsulated film resistor. 10. The safety arrangement according to claim 1, characterized in that the control unit (3) comprises 15 means (30, 31, 32) for measuring the total resistance of the series circuit. 11. The safety arrangement according to any one of the preceding claims, characterized in that the measuring arrangement for monitoring the safety spaces of the elevator comprises a position sensor that measures the position of the elevator car in the elevator shaft. 12. The security arrangement according to any one of the preceding claims, characterized in that the measurement arrangement for monitoring the elevator safety spaces comprises means for measuring a change in elevator car speed adjusted to the elevator car.